Implantable medical devices, such as electrical stimulation devices, may be used in different therapeutic applications, such as for deep brain stimulation, spinal cord stimulation, pelvic stimulation, gastric stimulation, peripheral nerve stimulation, or functional electrical stimulation of a target tissue site within a patient. An electrical stimulation device may be used to treat a variety of symptoms or conditions of a patient, such as chronic pain. In some therapy systems, an implantable electrical stimulator delivers electrical therapy to a target tissue site within a patient with the aid of one or more electrodes, which may be deployed by medical leads.